Trypanosoma brucei: cis-Aconitate and temperature reduction as triggers of synchronous transformation of bloodstream to procyclic trypomastigotes in vitro

Czichos, Joachim; Nonnengaesser, C; Overath, Peter

doi:10.1016/0014-4894(86)90033-0

Cited by 98 publications

(71 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1D and Tables 1, 2, lines 7). The cells continued to synthesize VSG albeit at a reduced rate [13]. Remarkably under these conditions proline oxidase and succinate oxidase activity could be demonstrated.…”

Section: Effect Of a Temperature Changefrom 37°c To 27°c On Bloodstrmentioning

confidence: 80%

“…Infectivity was unaltered 1 h after uptake but declined steeply thereafter (3 h w10%, 9 h wO.1-1%). This decrease in infectivity of the bloodstream forms was probably due to cell death rather than commitment to differentiation because, at least in vitro, the initial steps of transformation are reversible for several hours [13]. Microscopic examination of the gut contents confirmed that throughout the first day the blood meal contained a large percentage of dead or disintegrating bloodstream forms.…”

Section: Transformation In Tsetse Fliesmentioning

confidence: 91%

“…2) involved growth of trypanosomes in TM medium + 15% iFCS + CCA overnight at 37 "C above feeder cells. The cultures were then shifted to a temperature of 27°C [13,311. The advantage of this protocol is that iFCS does not lead to the aggregation of newly formed procyclic cells, which occurs with iHS.…”

Section: Tsetse Fliesmentioning

confidence: 99%

“…(1 1 , 131. a d . , It has previously been argued that the synchronous transformation of bloodstream forms of variant MITat 1.4 to dividing procyclic cells requires the combined action of two signals: a decrease in temperature from 37 "C to 27 "C and the addition of citratelcis-aconitate (3 mM each) or of 6 mM cisaconitate as inducers [13]. The question arises as to how the cells respond when only one of these signals is applied.…”

Section: Bloodstream Formsmentioning

confidence: 99%

“…Cells treated in this way did not transform although they differentiated in controls supplemented with 6 mM cisaconitate (equivalent to CCA, cf. [13]). Moreover, extracts of salivary glands (six glands sonicated in a bath-type sonicator in 1 ml medium) or of fly guts (two guts sonicated in 1 ml medium) did not stimulate transformation.…”

Section: Transformation In Tsetse Fliesmentioning

confidence: 99%

See 4 more Smart Citations

The effect of citrate/cis‐aconitate on oxidative metabolism during transformation of Trypanosoma brucei

Overath¹,

Czichos²,

Haas³

1986

European Journal of Biochemistry

Self Cite

140

View full text Add to dashboard Cite

Monomorphic bloodstream forms of Trypanosoma brucei, grown in the mammal, are deficient in aconitase and 2-oxoglutarate dehydrogenase and they do not respire in the presence of the substrates citrate, cis-aconitate, succinate, proline or 2-oxoglutarate. When grown in vitro low levels of aconitase, succinate oxidase and proline oxidase are detected.Addition of citratelcis-aconitate at 37 "C to bloodstream forms leads to the formation of aconitase and proline oxidase. Most cells undergo an 'abortive' transformation to non-dividing procyclic-like cells while some cells adapt to the presence of the citric acid cycle intermediates and continue to multiply as bloodstream forms.At 27°C and in the presence of citratelcis-aconitate bloodstream forms transform synchronously to dividing procyclic cells. Within 72 h the rate of respiration with proline, succinate and 2-oxoglutarate becomes similar to that in established procyclic cells while the rate of glucose oxidation decreases.The possible role of citric acid cycle intermediates in determining whether a trypanosome will retain the properties of a bloodstream trypomastigote or differentiate to a procyclic trypomastigote is discussed.The parasitic protozoan, Trypanosoma brucei, undergoes a series of differentiation steps during its cyclical development in the mammalian host and the arthropod vector, the tsetse fly [l]. Differentiation of bloodstream forms to procyclic cells, a process called transformation, is initiated in the mammal by the transition of dividing slender forms to intermediate and non-dividing stumpy forms, giving rise to a pleomorphic population. After uptake with the blood meal into the midgut of the fly, cells with stumpy morphology are considered to transform most readily to dividing procyclic cells.Transformation of pleomorphic as well as monomorphic populations of rodent-adapted strains which have a uniform slender morphology [2] can be studied in various in vitro systems [3 -91. Synchronous transformation requires two external signals, a temperature change from 37°C to 27°C and the addition of cis-aconitate and/or citrate as inducers Some of the complex morphological, ultrastructural and metabolic changes which characterize transformation have been studied in detail. First, the repression of the synthesis of the variant surface glycoprotein (VSG) in the coated bloodstream forms is an early event which is followed by coat [lo-131. release to form coatless procyclic cells [7, 8, 111. Second, transformation involves profound changes in energy metabolism [14-161. In bloodstream forms glucose is degraded solely by glycolysis to form two mol pyruvate/mol glucose. Reducing equivalents are transferred to oxygen via a unique mitochondrial glycerol-3-phosphate oxidase [17,18]. The promitochondrion lacks a functional citric acid cycle as well as a cytochrome-linked respiratory chain. Stumpy forms contain some mitochondrial enzymes, such as 2-oxoglutarate dehydrogenase and proline oxidase [19]. During transformation to procyclic cells a functional respiratory ...

show abstract

Section: Effect Of a Temperature Changefrom 37°c To 27°c On Bloodstrmentioning

confidence: 80%

Section: Transformation In Tsetse Fliesmentioning

confidence: 91%

Section: Tsetse Fliesmentioning

confidence: 99%

Section: Bloodstream Formsmentioning

confidence: 99%

Section: Transformation In Tsetse Fliesmentioning

confidence: 99%

See 3 more Smart Citations

The effect of citrate/cis‐aconitate on oxidative metabolism during transformation of Trypanosoma brucei

Overath¹,

Czichos²,

Haas³

1986

European Journal of Biochemistry

Self Cite

140

View full text Add to dashboard Cite

show abstract

Dealing with Multiple Environments: The Challenges of the Trypanosome Lifecycle

Calvo-Álvarez¹,

Bastin²

2021

Systematics and the Exploration of Life

View full text Add to dashboard Cite

Antigenic variation in trypansosomes: Secrets surface slowly

1996

View full text Add to dashboard Cite

Among pathogenic micro-organisms that evade the mammalian immune responses. Trypanosoma brucei has developed the most elaborate capacity for antigenic variation. Trypanosomes branched early during eukaryotic evolution. They are characterized by many aberrations, ranging from the unusual compartmentation of metabolic pathways to the heresy of RNA editing. The ubiquitous phenomenon of glycosylphosphatidylinositol-anchoring of eukaryotic plasma membrane proteins and RNA trans-splicing (trypanosome genes contain no introns), which adds an identical leader sequence to all trypanosome mRNAs, were first defined during studies of antigenic variation. Genetic transformation of trypanosomes and the high efficiency of gene targeting provide new opportunities to investigate the regulation of antigenic variation. There is every reason to expect trypanosomes to provide further surprises and insights into the evolution of genetic regulatory mechanisms.

show abstract

Trypanosoma brucei: cis-Aconitate and temperature reduction as triggers of synchronous transformation of bloodstream to procyclic trypomastigotes in vitro

Cited by 98 publications

References 16 publications

The effect of citrate/cis‐aconitate on oxidative metabolism during transformation of Trypanosoma brucei

The effect of citrate/cis‐aconitate on oxidative metabolism during transformation of Trypanosoma brucei

Dealing with Multiple Environments: The Challenges of the Trypanosome Lifecycle

Antigenic variation in trypansosomes: Secrets surface slowly

Contact Info

Product

Resources

About